Tenants are being moved out of another 31 Christchurch City Council housing units as investigations reveal they fall well below the building code.

The council this afternoon said it was closing 17 units in the Knightsbridge Ln complex in Aranui, seven units in the 13-unit Louisson Courts complex in Opawa and seven units in the 13-unit Avonheath Courts complex in Redcliffs.

The closures come after the council received the results of detailed engineering evaluations (DEEs) that showed the buildings have a seismic capacity of less than 34 per cent of the new building standard (NBS).

The other 12 units at Avonheath and Louisson courts had already been closed because of earthquake damage.

Council community services general manager Michael Aitken said the council was being cautious in closing the complexes but it had made a commitment to close buildings that were assessed as below 34 per cent of the NBS to ensure the safety of those using and living in its buildings.

The seismic capacity of the buildings at Avonheath Courts were assessed at 21 to 33 per cent of the NBS, while all four blocks at Knightsbridge Ln were estimated to be 22 per cent of the standard.

Louisson Courts had an estimated seismic capacity of less than 34 per cent of the NBS.

''This is a distressing time for residents, but council staff will be working closely with those affected over the coming days to identify alternative homes for them,'' Aitken said.

''There are other City Housing units available for those who wish to remain in a council-owned unit, which we hope will help to alleviate some of the disruption that will result from today's decision.''

The latest closures bring the number of city council housing units out of action because of quake damage to 482.

Last August, the council closed 36 units at Brougham Village in Waltham and in Setember it closed 24 units at Airedale Courts in central Christchurch.

It warned then that more closures were likely as it was only partway through the DEE process.

At that point it still had to complete detailed engineering investigations on about 50 council housing complexes considered at high risk because of their construction or age or because they were on technical category 3 land.

It is not scheduled to complete those investigations until June.

It will take another nine months to complete investigations on the council's remaining social housing stock.

So far the council has managed to find alternative accommodation for all those displaced from its units, but it has warned that if more closures occurred it may not have the capacity to rehouse the tenants.